This invention generally relates to the art of electrical connectors and, particularly, to connectors for electrically interconnecting flat flexible circuitry.
A flat flexible circuit conventionally includes an elongated flat flexible dielectric substrate having laterally spaced strips of conductors on one or both sides thereof. The conductors may be covered with a thin, flexible protective coating on one or both sides of the circuit. If protective layers are used, openings are formed therein to expose the underlying conductors at desired contact locations where the conductors are to engage the conductors of a complementary mating connecting device which may be a second flat flexible circuit, a printed circuit board or the discrete terminals of a mating connector.
A wide variety of connectors have been designed over the years for terminating or interconnecting flat flexible circuits with complementary mating connecting devices. However, problems still are encountered with such connectors when attempts are made to design the connectors with various desirable features. For instance, a known desirable feature in some electrical connector assemblies which include a pair of mating connectors, is to xe2x80x9ckeyxe2x80x9d the connectors so that only a given first connector can be mated with a given second connector. Such keying systems are difficult to achieve in connector assemblies for flat flexible circuitry, unless the keying features are added to the connector itself. In other words, a standard connector which accommodates a variety of flexible circuit configurations must be customized with the keying features alone, thereby increasing the cost of such connectors.
The present invention is directed to solving this problem by providing a unique keying system which uses the flat circuit, itself, as the means of providing keying features of the system.
An object, therefore, of the invention is to provide a new and improved connector assembly or system for electrically interconnecting the conductors of a flat flexible circuit to the conductors of a complementary connecting device, the connector system including keying features to prevent interchangeability of undesirable connectors in the assembly.
In the exemplary embodiment of the invention, a first connector has a body member for positioning the flat flexible circuit thereon. A second connector mates with the first connector and includes a pattern of keying projections insertable into a corresponding pattern of keying holes in the flat flexible circuit on the first connector.
According to one aspect of the invention, the body member of the first connector comprises a male body member having a leading edge at which the flat flexible circuit is positioned. The keying holes in the flat flexible circuit are located adjacent the edge. The circuit is wrapped about the leading edge of the male body member, and a plurality of recesses are formed in the leading edge behind the pre-positioned keying holes in the circuit so that the keying projections of the second connector can pass through the holes in the flexible circuit.
According to another aspect of the invention, the second connector includes a receptacle for receiving the first connector. The keying projections are located at the receptacle. The body member of the first connector comprises a male body member mateable in the receptacle of the second connector. Again, the flat flexible circuit is positioned at the leading edge of the male body member, with the keying holes in the circuit being located adjacent the edge.
Other objects, features and advantages of the invention will be apparent from the following detailed description taken in connection with the accompanying drawings.